The Role of Interventional Radiology in the Management of Pancreatic Pathologies
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Published online: 2020-01-10 THIEME Review Article 99 The Role of Interventional Radiology in the Management of Pancreatic Pathologies Ghali Salahia1 Sook Cheng Chin2 Ian Zealley2 Richard D. White1 1Department of Radiology, University Hospital of Wales, Cardiff, Address for correspondence Ghali Salahia, MD, MBA, Department United Kingdom of Radiology, University Hospital of Wales, Heath Park Way, Cardiff, 2Department of Radiology, Ninewells Hospital, Dundee, United CF14 4XW, United Kingdom (e-mail: [email protected]). Kingdom J Gastrointestinal Abdominal Radiol ISGAR 2020;3:99–114 Abstract Pancreatic pathologies are varied and wide-ranging, and a multidisciplinary approach is essential for effective diagnosis and management. We describe image-guided percutaneous (nonendoscopic) interventions in the management of pancreatic dis- ease, with emphasis on inflammatory and neoplastic pancreatic pathologies and on the transplanted pancreas. Image-guided treatments for the complications of pan- Keywords creatitis include percutaneous interventions on simple and complex peripancreatic ► interventional collections, pseudocysts, and fistulas. Vascular interventions predominantly focus on radiology the treatment of pseudoaneurysms, hemorrhagic pseudocysts, and arteriovenous ► pancreatic cancer malformations. Emerging ablative techniques for pancreatic cancer are promising ► pancreatic transplant and include percutaneous radiofrequency ablation, microwave ablation, irreversible ► pancreatitis electroporation, and electrochemotherapy. Image-guided interventions on the trans- ► peripancreatic planted pancreas commonly include percutaneous biopsy and drainage in addition to collection endovascular treatments of vascular complications. Introduction Pancreas transplantation offers diabetic patients the pros- pect of glycemic control free of exogenous insulin adminis- Approximately 20% of patients with acute pancreatitis will tration, with a significant improvement in quality of life and 1 develop complications that require intervention. These can reduction in diabetes-associated complications.6 Surgery 2 be classified into vascular and nonvascular complications : can, however, be complicated by a high rate of early techni- • Nonvascular complications include collections, bowel cal failure.7 Percutaneous and endovascular interventions are complications, and pancreatic fistulas.2 increasingly performed for the diagnosis of rejection and the • Vascular complications include peripancreatic arterial and treatment of vascular complications. venous pseudoaneurysms, venous thrombosis, and arte- 3 riovenous malformations (AVMs). Nonvascular Interventions Pancreatic adenocarcinoma is the 12th most common Drainage of Peripancreatic Collection malignancy and the 7th leading cause of cancer-related mor- Intra-abdominal collections and abscesses are the most com- tality globally.4 Most patients present late with either locally mon complication following acute pancreatitis.8 Collections extensive or metastatic disease.5 The aggressive nature, late are classified according to the revised Atlanta Classification presentation, and lack of effective therapies all contribute to into acute peripancreatic fluid collections, pseudocysts, the poor prognosis. Patients with more advanced disease will acute necrotic collections, and walled-off pancreatic necro- typically undergo either endoscopic ultrasound (US) or inter- sis9,10 (►Fig. 1). Symptomatic intra-abdominal collections ventional radiology-guided interventions to deliver either require imaging-guided drainage. When a collection is readily palliative or preoperative care.4 DOI https://doi.org/ ©2020 Indian Society of 10.1055/s-0039-3401335 Gastrointestinal and Abdominal ISSN 2581-9933. Radiology 100 Role of Interventional Radiology in the Management of Pancreatic Pathologies Salahia et al. Fig. 1 (A) Acute peripancreatic fluid collection (green arrow). (B) Multiple pseudocysts (yellow arrows) in the context of acute on chronic pancreatitis (note the pancreatic calcifications). (C) Acute necrotic collection (note absent enhancement of the pancreatic head). (D) Percuta- neously drained walled-off necrosis (blue arrow indicate the wall). (E) This had been subsequently infected (note the presence of gas). visualized on US, US-guided percutaneous drainage place- Infected pancreatic necrosis is often poorly marginated ment is generally the preferred choice as US is less expensive, and nonenhanced and may contain bubbles of gas. However, allows for real-time monitoring of the needle placement, and these features are not always present, and necrotic collec- is free from ionizing radiation.11 However, the combination tions without signs of infection at CT should be considered of US and fluoroscopy can improve on this by facilitating sterile until proven otherwise. Percutaneous drainage is safe needle puncture using US guidance followed by optimal generally avoided in this context due to the potential risk drain positioning using fluoroscopic guidance. of introducing infection. Deteriorating patients with high Journal of Gastrointestinal and Abdominal Radiology ISGAR Vol. 3 No. 1/2020 Role of Interventional Radiology in the Management of Pancreatic Pathologies Salahia et al. 101 clinical suspicion of infection may benefit from US-guided aspiration to rule out an infected pancreatic necrosis. When infected necrosis is present, large-bore or multiple percuta- neous drainage catheters should be sited in the collection as a bridge or as an alternative to surgical debridement.12 Guidelines from 2013 by the International Association of Pancreatology and the American Pancreatic Association advise postponing all forms of invasive intervention in patients with infected necrosis, preferably until 4 weeks after the onset of disease.13 The rationale behind this is fourfold. First, antibiotics alone might be sufficient as treatment. Second, diagnosing infected necrotizing pan- creatitis is often easier in the later stages of the disease, when all other sources of infection or systemic inflamma- tory response have been ruled out. Third, catheter drain- age is typically easier once the collection has become Fig. 2 CT-guided guided drainage of peripancreatic collection through more liquefied and the stage of walled-off necrosis has a right posterior approach. been reached. Fourth, endoscopic transluminal drainage requires a walled-off collection. Pseudocyst Gastrostomy In theory, it is not always necessary to wait several weeks Iatrogenic communication between a pseudocyst and hollow until full encapsulation of peripancreatic collections and per- viscus can be formed to enable drainage (►Fig. 3). Internal cutaneous drainage can be performed safely and successfully gastric drainage of pancreatic pseudocysts is now commonly 14 in the first weeks after the onset of disease. If there is no performed under endoscopic US guidance.19 CT-guided per- technical reason for postponing catheter drainage, patients cutaneous technique cannot regularly provide an adequately with infected necrotizing pancreatitis might benefit from wide cystogastrostomy opening.11 Surgical cystogastrostomy earlier catheter drainage in terms of reducing the rate of is usually reserved for necrotic collections that do not abut complications and length of hospital stay. This is also the case the gastrointestinal tract and may be found in the retroperi- in the context of abdominal compartment syndrome. More toneal space.19 recently, the Dutch Pancreatitis Study Group is undertaking a The percutaneous approach typically necessitates two randomized controlled trial (POINTER [postponed or imme- stages, with the pseudocyst initially being drained percuta- diate drainage of infected necrotizing pancreatitis]) that will neously through a transgastric route as a temporary bridge compare immediate and delayed catheter drainage in an before converting into an internal cystogastrostomy drain- attempt to further improve the outcome of these severely ill age through a double-J stent or by pushing the percutaneous 15 patients. drain into the stomach.20 When a collection is located deep in the abdomen or is There is no consensus about the duration of drainage poorly visualized on US, computed tomography (CT) offers through pseudocyst gastrostomy. After the introduction of this adequate guidance to allow safe placement of percutaneous technique in 1984, pigtail catheter removal was initially advised 16 drains. after 3 months. The technique has since evolved such that the After placement and aspiration of fluid, self-locking pigtail catheter is left in situ for at least 1 year to more than 3 years if drains of size 8 to 12 Fr are left in place and irrigated with there is a concern that catheter removal would lead to symp- 10 to 20 mL of sterile saline three times daily. Catheters can tomatic recurrence. Catheter removal by forceps during routine be upsized to a maximum of 28 F, as the clinical situation gastroscopy in the outpatient setting has been reported.21 8 evolves if smaller drains prove inadequate. Technical success in percutaneous catheter placement External drainage of peripancreatic collections may fail in is greater than 90%, with an immediate complication rate the setting of abnormal pancreatic ductal anatomy. In a study of around 6% and a mortality rate of 1%.18 Secondary infec- by Nealon et al, there was a statistically significant difference tion with abscess formation is not uncommon, occurring in in successful percutaneous drainage between patients with around 11%.21